• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.6
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• pp.99-104
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• 2005

The CARB in USA has demanded OBD functions that detect any deterioration of performance of OTS as well as a simple defect of OTS which can affect emission to meet the reinforced emission regulation. In this paper, OTS plausibility monitoring functions to meet the demand from CARB are discussed. The output from OTS is used for the diagnostics of the torque converter clutch stuck and the gear ratio synchronous error. It is possible to diagnose the abnormality of OTS function by considering the oil temperature characteristics which changes according to the driving status of vehicles. In result, the OBD regulations of the CARB can be satisfied obligating car manufacturer to detect any problems in OTS functions which can affect emissions.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1136-1137
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• 2006

통합항해시스템이라 함은 자동화된 선박의 운용에 관한 것으로, 다양한 항해 센서(GPS, Gyro, Speed Log, echo sounder)를 이용하여 선박의 항해에 필요한 각종 정보를 입수하여 최적의 항로를 설정해주고, 운항의 안정성과 효율을 극대화시키는 시스템을 지칭한다. 즉, 선박의 운항에 필요한 다수의 모듈들을 독립적으로 운용하는 것이 아니라 이를 통합된 형태로 운용하여 효율을 극대화시키는 시스템이 통합항해시스템이라 할 수 있다. 통합항해시스템은 다양한 항해 센서들과 항해 시스템으로 구성되며, 다양한 항해 데이터들은 항해 센서로부터 수신하여 처리하는 동작을 수행한다. 즉, 통합항해시스템은 다수의 센서들로부터 수신된 정보를 평가하고 잠재적 위험과 무결성 저하에 대해서는 적절한 경고를 제공하여야한다. 따라서, 항해센서 데이터의 유효성(Validity) 및 모호성(Plausibility) 검사와 무결성 감시(Integrity Monitoring)는 통합항해시스템의 필수적 기능이라 할 수 있다. 본 연구에서는 IEC 61924 규격에 의한 항해센서로부터 수신된 항해데이터가 정확하고 유효함을 가지는 지에 대한 가치평가의 척도와 독립적인 데이터 소스로부터 데이터를 비교하여 검증하는 무결성, 정확도 이내의 정보를 완전하고 명확한 방법으로 사용자에게 제공하는 무결성 감시의 방법을 제시하며, 항해센서들에 의해 취득되는 항해 데이터의 무결성 검사를 통한 유효성, 적용가능성, 무결성의 평가방법을 기술한다.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1409-1411
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• 2003

The application of simulated KOMPSAT-2 imagery to monitor graveyards is to be developed. Positions calculated from image were compared with those obtained from Geographic Positioning System. With 24 checkpoints, the position of graveyards showed within 5-meter range. Unsupervised classification, supervised classification, and objected-orientation classification algorithms were used to extract the graveyard. Unsupervised classification with masking processes based on National topographic data gives the best result. The graveyards were categorized with four types in field studies while the two types of graveyards were shown in descriptive statistics. Cluster Analysis and discriminant analysis showed the consistency with two types of tombs. It was hard to get a specific spectral signature of graveyards, as they are covered with grasses at different levels and shaded from the surrounding trees. The slopes and aspects of location of graveyards did not make any difference in the spectral signatures. This study gives the basic spectral characteristics for further development of objected-oriented classification algorithms and plausibility of KOMPSAT-2 images for management of mountainous areas in the aspect of position accuracy and classification accuracy.

• Smart Structures and Systems
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• v.17 no.2
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• pp.209-230
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• 2016

The Canton Tower is a high-rise slender structure with a height of 610 m. A structural health monitoring system has been instrumented on the structure, by which data is continuously monitored. This paper presents an investigation on the identified modal properties of the Canton Tower using ambient vibration data collected during a whole day (24 hours). A recently developed Fast Bayesian FFT method is utilized for operational modal analysis on the basis of the measured acceleration data. The approach views modal identification as an inference problem where probability is used as a measure for the relative plausibility of outcomes given a model of the structure and measured data. Focusing on the first several modes, the modal properties of this supertall slender structure are identified on non-overlapping time windows during the whole day under normal wind speed. With the identified modal parameters and the associated posterior uncertainty, the distribution of the modal parameters in the future is predicted and assessed. By defining the modal root-mean-square value in terms of the power spectral density of modal force identified, the identified natural frequencies and damping ratios versus the vibration amplitude are investigated with the associated posterior uncertainty considered. Meanwhile, the correlations between modal parameters and temperature, modal parameters and wind speed are studied. For comparison purpose, the frequency domain decomposition (FDD) method is also utilized to identify the modal parameters. The identified results obtained by the Bayesian method, the FDD method and a finite element model are compared and discussed.